Lubricants



Patented Nov. 24, 1953 LUBRICANTS William N. Axe and William 8. Whitney,Bartlesville, Okla, assignors tolhillips Petroleum Company, acorporation of Delaware No Drawing. Application March 26, 1951,

Serial No. 217,359

9 15 Claims. 1

This invention relates to improved lubricants. In one embodiment itrelates to new gelation agents and their preparation, and to their usein the manufacture of ashless greases. In another embodiment .thisinvention relates to im proved lubricating oils. In another embodimentit relates to the manufacture and use of new additive materials inlubricating oils. In still another embodiment it relates to thereduction of .the deposition and accumulation of sludge on oillubricated engine parts, in an engine system. IIIhis application is a.continuation-in-part of our QQmnding application Serial No. $4,575.filed A l fi 15, 5-

In the manufacture of lubricants, a great many substances have been usedas gelation agents. These materials are incorporated with mineral oilsnder the proper conditions to produce lubricants and lubricatinggreases. The most com- Anon among these gelation agents are the sodium,calcium, and aluminum salts of the higher molecular weight fatty acids.Certain other metal salts of fatty acids have also been used, howevermuch less frequently. In some instances, mahogany acids have been usedin place of the fatty acids. Such mahogany acids are the result of theaction of sulfuric acid on petroleum oils, and their composition varieswidely depending on the oil treated, and conditions of treatment, andthe volume and strength of sulfuric acid used. Usually they are used inthe form of their sodium or calcium salts.

alts 'of the fatty acids and mahogany acids just described are oftencalled gelation agents. it is one of their properties that when added tooils o'f'th'e' proper type and under certain conaiti m they will causegelling and thickening of theioilsjmaking them have utility aslubricants 'll'lllblioat?!g"'greases.

At the'prese'nt time it is common practice to enhance or modify certainof the properties of lubricating oils through the use of variousadditi'ves or improvement agents. The lubricating oils employed in-ir'iternal combustion engines, such'a's automotive, light aircraft, anddiesel engines in particular, require'the use of additive to" renderthem serviceable under the adv;e environmental conditions encountered inenginesl' Among the various additives emplayed "in modern eng ne oils,one'of the most iipnortaht'is ,the ityhe ivhich'ae to preventaccumulation of sludge in the crankcase and on the cylinder .wlalls',thereby preventing sticking of thepifilon rings, and the io'rmation ofvarnishg e'qogung on the pistons'and cilin'der walls.

jicau'se'of their general jfunctiondf maintaining a clean engine,additives'of this nature are termed idetergentsf although it is nowunder stood thatthey have little utilityin cleaning a dirty engine butby virtue of dispersant activity prevent or greatly retard enginefouling.'

It'has long'heen re ognized 'thatgas'li content 2 of detergents andother additives in a lube oil employed in engine operation contributesto upper cylinder deposits which in turn contribute to and predisposetoward pro-ignition, valve burning; and general rough engine operation.The use of ash-forming detergmt additives in engine operation, is forthese reasons, often inadvisable, particularly in aircraft engines. Ourinvention is concerned with new and novel ashless 011 detergents, andwith improved lubricating oil containing such detergents.

It is an object of our invention to provide improved lubricants. Anotherobject is to provide improved lubricating reases. Another object is toprovide improved lubricating oils. Another object is to provide additiveagents for imparting improved properties to lubricating oils. Anotherobject is to provide gelation agents, and for their manufacture, and fortheir use in the manufacture of ashless greases. Another object is toprovide ashless lubricating oil detergents. Another object is to providea method for the manufacture of new and improved lubricating ,oildetergents of the sulfonate type. Another object is to provide a methodfor preventing an accumulation of oil degradation products ,on oillubricated engine parts. Other objects will be apparent to those skilledin the art from the accompanying discussion and disclosure.

In accordance with a broad embodiment of our invention we have providedimproved ashless lubricant compositions comprising mineral oilsincorporated with a guanidine salt of an organic sulfonic acid selectedfrom the group consisting of synthetic guanidine alkyl aryl sulfonatesand guanidine petroleum sulfonates, and containing om -1 0. 0 w i P r ce0 h i apid a salt.

The term lubricant is used herein to denote not only a lubricatinggrease but also a lubricating oil, and includes compositions formed byincorporating a guanidine sulfonate of the type described above with amineral oil.

We have discovered that certain alkyl aryl rsulfonic acids can beneutralized with guanidine r b si ue i n is i mm ili e aryl sulfonates.pertain of these new and novel urmise s r r u bi e di readily n-m fi f a9' a ge s ag nt o o mi m m d greases of the ashl ess type, wh le certainothe ofrelatively"high"molecular weight are oilsoluble'and.whenidisslolved'in a lube oil base stock impart valuable detergentproperties toit thus. forming improved lubricating oils. We have furtherdiscoveredfthat certain petroleum sulfonic acids can be neutralized withguanidine or a basic guanidin salt and that certain guanidine petroleumsulfonates thus produced are oilsoluble, and when dissolved in a baselube oil stock impart valuable detergent properties to it.

Additionally, as described hereafter, other ,g'uanidine petroleumsulfonates differing from the detergent types principally in molecularweight and degree of sulfonation have pronounced gell ing tendencieswhen dispersed in oil and may be utilized to advantage in thepreparation of greases.

The guanidine allryl aryl sulfonates as grease gelation agents containfrom 17 to 35 carbon atoms in the molecule, although certain of theseserve also as detergents in oil systems, dependent to a large degreeupon the concentration of the guanidine salt added, particularly thoseformed from alkyl aryl sulfonlc acids containing at least 24 carbonatoms per molecule. However, when we employ guanidine alkyl arylsulfonates as oil detergents, we prefer to employ those formed fromalkyl aryl sulfonic acids containing from about 40 to 70 carbon atomsper molecule or higher. When employing our novel guanidine petroleumsulfonates as oil detergents, We employ those formed from petroleumsulfonic acid containing at least 40 carbon atoms in the molecule.

In forming our lubricating grease compositions we disperse the guanidinealkyl aryl sulfonate in a mineral oil base stock to form a compositioncontaining from 5 to 60 weight per cent of the guanidine alkyl arylsulfonate.

The alkyl aryl sulfonic acids, which on combining with guanidine formour gelation agents, may be produced by the alkylation of an aromaticnucleus such as benzene, naphthalene, diphenyl, or anthracene, or theiralkyl derivatives, with olefins which boil in the approximate range of190 to 315 C. When alkylating alkyl aromatics such as, for exampletoluene or Xylene, a fraction of olefins in the 190 to 315 C. range mustbe selected so that after alkylation, the total number of carbon atomsin the alkyl groups is not more than about 20. The preferred boilingrange of the alkylating olefins is usually 190 to 315 C. and sucholefins generally contain from about to carbon atoms per molecule,however, a narrower range of, say 230 to 250 C., may often be desirableand is quite satisfactory. Straight chain olefins having the double bondin the one position are well suited for use in our invention. Branchedchain olefins are also quite applicable. It is to be noted, however,that a branched chain olefin containing the same number of carbon atomsa straight chain olefin acts as a straight chain olefin containing lesscarbon atoms insofar as oil-solubility is concerned.

A suitable gelation agent is a guanidine salt of an alkyl aryl sulfonicacid in which the alkyl group contains at least 10 carbon atoms. Whenthere are more than ten carbon atoms present in the alkyl groups, asatisfactory gelation agent is one with at least one alkyl groupcontaining 10 carbon atoms. Another satisfactory salt or gelation agentis a guanidine alkyl aryl sulfonate having two ailryl groups having atleast 8 carbon atoms each, Another is one having three alkyl groups ofat least 6 carbon atoms each. Generally speaking, when only one alkylgroup is present in the guanidine alkyl aryl sulfonate, it shouldcontain at least 10 carbon atoms, and no matter how many alkyl groupsare present they should preferably contain a total of not more thanabout 20 carbon atoms.

The above described guanidine alkyl aryl sulfonates having utility bothas gelation agents and as oil detergents, and the guanidine petroleumsulfonates described more fully hereinafter are new compounds.

Any conventional method is suitable for alkylating aromatics witholefins to produce alkyl aromatics for sulfonation and subsequentneutralization in the preparation of our synthetic guanidine alkyl arylsulfonates. Such a method may employ sulfuric acid, hydrofluoric acid,or boron trifiuoride as catalyst for the alkylation; however, theinvention is not to be limited by the particu lar means used forallrylating aromatics. Other methods for obtaining alkyl aromatics, suchas alkylation of aromatics with alcohols, alkyl halides, ethers, oresters, are well suited for our invention. Suitable alkylatablearomatics are those containing only one rin such as benzene, toluene,and xylene as mentioned above. Satisfactory results may also be obtainedfrom multiring compounds, in particular naphthalene, diphenyl,anthracene, and their lower alkyl homologues. It is generally preferredthat not more than three rings be present in the aromatic hydrocarbon.The compounds, alkylated with olefins as described above, are thensulfonated by suitable means, such as by fuming sulfuric acid, as iswell known to those skilled in the art, to produce alkyl aryl sulfonicacids. However, our process is not to be limited by the means ofsulfonation employed. These latter compounds are then combined with thestrong organic base guanidine to form a gelation agent which is theguanidine salt of the sulfonic acid. Usually this material may be usedto thicken an oil and to obtain a lubricant having the form of a solidor semisolid cake, but in special cases where extremely light lubricantsare desirable, the final lubricant mixture may be in the form of aliquid, usually being thick and havin a texture similar to syrup orhoney. When referring to the neutralization of l the alkyl aryl sulfonicacid with a guanidine compound in either the specification or theclaims, we mean to include also the use of guanidine by itself.

One specific method for the preparation of one of our novel guanidinealky aryl sulfonates is as follows. A suitable alkyl aryl sulfonic acidhaving the requisite number of alkyl carbon atoms as described above, isdissolved in a low-boiling alcohol such as, for example isopropylalcohol or butyl alcohol. To the thus-formed solution is added a molarexcess of a concentrated aqueous solution of a guanidine compound,suitably the carbonate. The solution separates into an alco hol layercontaining the guanidine alkyl aryl sulfonate and a Water layer. It ispreferable not to use an alcohol boiling below isopropyl alcohol becauseinadequate separation of the alcohol layer from the water layer isobtained. The alcohol layer is removed by suitable means, such asdecanting, and then filtered to remove any solid material, after whichit is evaporated to recover the guanidine alkyl aryl sulfonate. If nosolid material is present in the alcohol layer. it may be evaporateddirectly without filtering. For further purification (if desired) theguanidine sulfonate may be extracted with anhydrous alcohol, the alcoholthen being evaporated In order to make an improved grease in accordancewith our invention, the novel guanidine alkyl aryl sulfonate alreadydescribed is admixed ith a mineral oil of suitable properties such asviscosity, density, flash and fire, pour-point, specific gravity, color,and specific dispersion, chosen in accordance with the type of greasedesired. Generally 5 to 60 weight per cent of the salt is adequate andit is often preferred to use 15 to weight per cent. Ranges of propertieswhich cover oils suitable for use in making lubricants in accordancewith our invention are given in the aoeam following table. Broadly, anoil with some hilaricating properties is desirable and may have aviscosity in the range of 50 to me SUB 100 1 5, but may go as high as2000-4009 SU S rec F. It is preferable that the viscosity index of theoil be above so, although lower viscosity index one may be used. Morenarrow and preferred ranges tor the mineral oil are the toliowing:

Viscosity, SUS at 1'60 F 125-500 itch-active index, N 1.4%0-L4'920Specific gravity D4 6.84-06-9.=8890 Usually it is necessary to heat thesalt and oil so that the salt becomes a liquid and will dispersethroughout the 011, i. e., to a temperature above the melting point ofthe gelation agent to insure a homogeneous mixture of components. Caremust be taken, however, not to heat the mixture to such a temperaturethat decomposition of the particular salt used tak s place. Thetemperature to which it will be necessary to heat the oil and salt willbe readily discernible to one skilled in the art of grease making. Afteradmixing the salt and mineral oil at an elevated temperature, themixture is cooled by suitable means. It is preferable to chill thegrease rapidly, that is, bring it to room temperature within a period ofabout 10 minutes or less. Following such cooling, the material is milledto a smooth grease. Grease milling is ordinarily considered as a simpleprocess for smoothing out and obliterating t'he clots or lumps of heavygrease formed by chilling. Suitable apparatus for such processing arestone buhr mills and the like.

Conventional grease manufacturing equipment frequently maybe utilizedfor the practice of our invention; however, the invention is not to belimited by any particular type used. For example, a jacketed kettlethrough which may be clrculated a heat transfer material is satisfactoryfor dispersing the gelation agent in the oil. At times, it may bedesirable to pass a coolant through the jacket so that the mixture maybe cooled quickly once the proper amount of gelation agent hasbeendispersed. In cases or higher concentration, discharge of the dispersionand external cooling may be necessary due to the firm texture of .thecooled mass. It is often advantageous to use mechanical stirring means.because by so doing the time of manufacture is greatly reduced.

As stated above we have found that certain guanidine petroleumsulfonates can be utilized as ,gelation agents in the manufacture ofgreases. Those guanidine petroleum sullonates are formed from petroleumsulfonic acids containing from to 10, preferably from '22 to 35, carbonatoms in the molecule, and can be prepared by the sulfonation of a'lubeoil stock of SAE 10 or 20 grade followed by neutralization of thesulfonate formed with guanidine or a guanidine basic salt. We have foundthat in preparing the guanidine petroleum sulfonate gelation agents inthis matter, some oil-soluble guanidine sulfonates may be formed.However it is generally unnecessary to remove these oil-solublesulfonates for use of the .guanidine sulfonate product as a gelationagent. We have also found that by sulfonatirrg .a heavy petroleumfraction, say as high as one containing 70 to 80 carbon atoms in themolecule and by neutralizing di- 'or polysulfonic acids thus formed,with guanidine, the resulting polyguanldine sullonates are excellentgelation agents, and have such a molecular weight that the moleculecontains one sulfonate group per 20 to carbon atoms.

In accordance with one mbodiment of our 5mvention we have providedimpmwd mill compositions comprising oils and 11mm 0.1 to 25 weight percent of an nil-soluble glilimidime salt of an organic sulfonic acid, asan ashless oil detergent, selected from the gmup consisting of syntheticguanldine alkyl aryl sulfonates and guanidine petroleum suitonates.Higher concentrations of active ingredient may be used insofar as theyare compatible with viscosity manurements and economics.

In another embodiment of our invention we provide a method forpreventing accumulation of sludge and associated deteriorative oilreaction materials on oil-lubricated engine parts by incorporating withthe lubricating oil as an ashlessdetergenit an oil-soluble guanidinesalt of the type described above.

In another embodiment we provide a method for the manufacture of theoil-soluble detergents described above.

In the preparation \of ashless detergents of the sulfonate type theemployment of derivatives of ammonia as the cationic portion of themolecule is one approach. However, in the conversion of the petroleumsulfonic acids of commerce to ashless lube oil detergents, therequirements od good thermal stability and resistance to hydrolysis tendto discourage ammonia, amines and ordinary miatemary bases as tribenzylmethyl ammonium hydroxide and the 0n the other hand, the imide of urea,guanidine, is a strong base, and while unstable in the form of the freebase, it exhibits a high degree of thermal and hydrolytic stability inthe form of its salts of strong acids and to a lesser extent as salts ofweak acids. As discussed herein and shown in our aforementionedcopending application, guanidine salts of certain synthetic alkyl arylsuli'onic acids of moderate molecular weight are quite useful asthickening agents in the preparation of greases. Likewise, we have foundthat certain guanidine salts of commercially available petroleumeulfonic acids exhibit gel-forming tendencies, when associated withmineral oils. detrimental to their application as lubricating oildetergents. In general the unfavorable solubility relationships ofguarndi ne sul-tonates necessitate special selection of species andspecial treatment prior to their application in lubricating oils whereexcessive deviation from true solutions cannot be tolerated.

We have new discovered that oil-soluble guanidine salts of petroleum'sul l onic acids can be termed by careful selection of sulfonationstocks and by appropriate refining of the crude sulionic acllls and/orguanldine sulfonates. We have furflier found that the certainoil-soluble and ashiree guanidine sulfonates of this invention whendissolved "in oil provide excellent detergency in the operation ofinternal combustion engines.

The hydrocarbon raw materials for production of 'oil detergents of thisinvention may be of synthetic or petroleum origin although the latterare preferred for economic reasons. In the case of syntheticsulfonati-on stocks alkylated aromatics of about 24 carbon atomsrepresent the approximate lower limit of useful guanidine alkyl aryl'sulfonates from the oil solubility standpoint. Since 'guanidinesu'lfonates even in this molecular weight range exhibit somewhat limitedsohfbility in lubricatin oil, we prefer to employ synthetic hydrocarbonsulfonation stocks of about 40 carbon atoms per molecule and higher toinsure additive solubility in all concentrations and in various typesand viscosity grades of oil. In the case of naturally occurringpetroleum sulfonation stocks, adequate oil solubility of the guanidinesulfonates can only be realized from bright stock fractions having atleast 40 carbon atoms per molecule with most favorable results beingobtained with oils having from 50 to '70 carbon atoms per molecule.

In the practice of one embodiment of our invention, the following stepsare involved in the manufacture of our guanidine petroleum sulfonateashless detergents: (l) sulfonation; (2) neutralization of the sulfonicacid formed, with guanidine; (3) separation of oil and oil-solubleadditive from gel-forming oil-insoluble components; and (4) preparationof additive-oil solutions of known concentration. In the case ofsynthetic hydrocarbons such as alkylated aromatics, conventionalsulfonation techniques may be applied as already discussed.

When employing our preferred solvent-extracted bright stocks in thepreparation of our guanidine petroleum sulfonate detergents, anhydrousSO3 dissolved in ethylene chloride is the sulfonation agent of choicesince such hydrocarbons are resistant to fuming acid and because themore potent SO: produces a rapid clean cut sulfonation reaction withvirtually no formation of acid sludge. The crude sulfonation product maybe subjected to purification as such, or it may be directly neutralizedwith aqueous guanidine or preferably guanidine carbonate. In the formercase, the crude sulfonation reaction mixture is extracted with water toremove inorganic acids thus conserving guanidine in the neutralizationstep to follow. Th sulfonic acids are thereafter extracted from thewashed reaction mixture with an alcohol of 1 to 6 carbon atoms such asisopropyl alcohol. The alcoholic solution, i. e., extract, is thenneutralized with a suitable guanidine derivative. An alcohol-insolubleportion separating on neutralization and which contains the desiredproduct is repeatedly extracted with alcohol until all oil-insolublesulfonates have been removed. Molecular weight determination andquantitative nitrogen assay on this material provide a convenient meansof computing the final sulfonate concentration. If the crude sulfonationreaction product is directly neutralized without purification, the crudeneutralized sulfonation product, i. e., the mixture of oil and guanidinemonosulfonates, polysulfonates, sulfate, sulfite and carbonate, iswashed with water to remove sulfate, sulfite, carbonate, and somepolysulfonates, and the purified residue is then extracted with analcohol of 1 to 6 carbon atoms per molecule at about '70 to 75 F. inorder to remove oil-insoluble guanidine sulfonates.

Ordinarily the extraction of the neutralized petroleum sulfonic acid iscompleted on reduction of the nitrogen content to about 1.0 to 1.5 percent which provides an oil concentrate having a nominal sulfonatecontent of about to percent active ingredient. Since in many cases theunreacted carrier oil may have an undesirable high viscosity, it isoften advantageous to carry out an exhaustive fractional extraction thuscompletely denuding the carrier oil of its sulfonate content andutilizing those sulfonate fractions showin complete oil solubility inpreparing the final assayed and diluted additive.

The purification of the petroleum guanidine sulfonates is an importantfeature of the present invention since the total petroleum guanidinesulfonates formed are found by engine tests to be not only devoid ofdemonstrable detergent activity, but actually to contribute to overallengine sludge and varnish. While the alcohol extraction step referred tohereinbefore apparently serves to segregate oil-soluble fromoil-insoluble guanidine sulfonates other effects may be operative andpertinent to the ultimate effectiveness of our novel detergents.

One method by which an oil-soluble guanidine alkyl aryl sulfonatedetergent of our invention can be prepared comprises the conventionalalkylation of an aromatic hydrocarbon such as zenzene, naphthalene,diphenyl, or anthracene, or their alkyl derivatives, with an olefin of amolecular weight selected so that the resulting alkylate contains atleast about 24 carbon atoms per molecule, and preferably from 40 to 70carbon atoms or even higher. Suitable oleflns may include decene,octadecene, triacontene and the like or commercial mixtures of sucholefins. In most instances more than one alkyl group is introduced intothe aromatic nucleus in order to arrive at a sulfonation stock ofadequate molecular weight. The resulting alkylate is then sulfonatedemploying any suitable sulfonating agent such as fuming sulfuric acid,sulfur trioxide, or the like, and the sulfonic acid thus formed isreacted with guanidine or a basic salt of guanidine, as for exampleguanidine carbonate, to form a guanidine alkyl aryl sulfonate detergentof our invention.

One procedure for carrying out this latter reaction comprises dissolvingan alkyl aryl sulfonic acid, formed as indicated above, in a lowerboiling alcohol as a solvent, as for example isopropyl alcohol or butylalcohol. To the thus formed alcohol solution is added a stoichiometricexcess of a concentrated aqueous solution of a quanidine compound,preferably the carbonate. The resulting reaction solution separates intoa solvent layer containing the guanidine alkyl aryl sulfonate, and awater layer. It is preferable to use an alcohol as a solvent containingat least 3 carbon atoms in the molecule since inadequate separation ofthe alcohol and water layers otherwise occurs. The alcohol and waterlayers are then separated, as for example by decantation, and thealcohol is removed from the solvent layer by vaporization to provide thedesired guanidine alkyl aryl sulfonate detergent material. In some casessolid materials may be present in the solvent layer, in which case it isdesirable to filter the layer and then vaporize the alcohol solvent fromthe filtrate.

In a more specific embodiment of our invention relating to themanufacture of oil-soluble and ash-free quanidine petroleum sulfonateshaving exceptional lube oil detergent properties, a sulfonation basestock is selected from the more viscous or bright stock fractions ofetroleum. More specifically we prefer to employ a deasphalted andsolvent refined petroleum fraction having a viscosity range betweenabout and 700 SUS 210 F. A preferred sulfonation stock is apropane-fractionated, solvent-extracted and dewaxed Mid-Continent oil ofabout 200 to 230 SUS 210 F. having a viscosity index of about to orhigher. Similar bright stocks of Pennsylvania or naphthenic origin whileless desirable may be used. It will be appreciated by those skilled inthe art that by the term "propane-fractionated is meant fractionation ofthe oil or bright stock with propane to effect deasphaltization and alsoseparation of oil components on basis of viscosity and that by solventrefining is. meant the removal by solvent extraction of the more highlyaromatic fractions from the dess- Dlmlted bright stock. In the latterstep any suitable selective solvent can be employed. amongwhich areincluded phenol, cresylic acids. chlorimated others such as chloroethylether. nitrobenzone, furfural, and the like. The deasphalted and solventrefined oil is generally dewaxed p ior to sulfonation although dewaxingcan be dispensed with if complete segregation of sulfonio acids from thewaxy oil is carried out at temperatures above the solution temperatureof the wax. In any case prior deasphaltingand extraction is definitelyrequired. In general, lube stocks lightor than about 80 SKIS 210 F. areunsatisfactory for use in the manufacture of our lubricatins oildetergents since the resulting guanidine petroleum sulfonatos are notsufiicientiy soluble in oil to serve as detergent additives.

A feature of our success in sulfonating the high molecular weight oilsof this invention is the employment of stabilized liquid sulfur trioxideas the sulfonating agent. Our procedure for sulfa mating with thisreagent is well known in the art and involves dissolving the anhydrousliquid $03 in from 2 to 5 times its weight of dry ethylene chloride toprovide an easily manipulated sulfonation reagent. The hydrocarbonsulfonaticn stock may likewise be. dissolved in ethylene chloride or anyother suitable non-reactive solvent such as carbon tetrachloride,chloroform, nontane, hexane, or the like.

Sulfonation in a preferred embodiment can be carried out in a continuousflow system or in batch agitators. In either case the quantity of SO:added is ordinarily adjusted to give a molar ratio of S03 to sulfonationstock of between about 1:1 and 3:1. The reaction between the hydrocarbonand S03, even in the case of extremely viscous bright stocks havingmolecular weights in the range of 800 to 900, is very rapid andexothermic. Sulfonation temperatures are ordinarily controlled withinthe range of about 50 to 200 F. with a preferred operating range between80 and 130" F. Lower temperature may be employed without seriouslyslowing down reaction rates, but no particular advantage accruestherefrom. At temperatures above about 200 F. excessive oxidation withliberation of sulfur dioxide occurs.

On completion of the sulfonation reaction sufflcient aqueous guanidinecarbonate solution is added to bring both the oil and water phases to apH value within the range of 6 to 8 as determined on a pH meter. Theaqueous phase is separated and water-soluble reaction products such asguanidinc sulfate, sulfite, carbonate and certain polysulfonates arewashed from the oil phase with water or water containing some lsopropylalcohol ii serious emulsion difficulties are encountered. Separation ofoil-insoluble sulfonatcs is accomplished by extracting the water-washedoil solution and/or dispersion with an anhydrous alcohol. We have foundthat petroleum sulfonotes of poor oil solubility characteristics aremore soluble in anhydrous alcohols such as isopropyl alcohol than arethe oil-soluble suliohates. Since the guanidine petroleum sulfonates arestrongly surface-active, emulsion formations can be avoided in thisextraction step by dissolving the oil sulfonate mixture in an equalvolume of hot alcohol, 1. e. above 100 F. and as high as 150 F. orhigher, as for example at its boiling point, and then slowly cooling toroom temperature, e. g., to below about 100 F. followed by separation ofthe alcoholic phase. We have found that continuation of this batchwisefill traction is desirable until the alcohol extract no longer formsguanidine pierate when treated with alcoholic oi rie acid. For reasons nlea lo on. oeterssnhactivc duanidmo De trolcum sulizonates do. no reactw th alcoholic acid. Ordinarily 3 to 4; extractio s usinfl: one volumeor alcohol per volume or oil per extraction sufliccs to c mp e e he desred eparation. Resi ual. alcohol str p ed f om the oil-detergent solut nto give a concentrate, suit, able for direct addition o lubricating ils.The activity or potency oi the detergent is determined from its nitroaencon ent on the basis of a s oichiometric N/S weight ratio of 1.33/1. Thesul-i tenets sulfur c ntent is th ir computed to ar iv at the quantityof active ing edient available. On the basis of equival n sulionic acidra icals. our euanidine petroleum su ionates are equal to or betterthan. conv nti nal al um and barium. suifonate detergents An alternativealcohol extraction procedure may be employed where the viscosity of theunsulfonated oil is too high for use in light lubricants. Thus,extraction may be carried out at moderately elevated temperatures ofabout to F. until substantially complete removal of sulfonate isrealized. The picric acid test, previously referred to, when applied tothe extract fractions is a useful first indication of the oil-solubilityof product sulionates. After evaporation of the alcoholic solvent, thesemi-solid or plastic guamdine sulfonatcs are dissolved in a carrier oilof suitable viscosity, the con/centre: tion of active ingredient beingdetermined by the nitrogen content as previously described.

Another alternative in the petroleum sulfonate purification procedureresults in substantial economy with respect to guanidine carbonate butrequires additional investment in corrosion resistant equipment. In thisvariation the crude sulfonation mixture is washed free of soluble acidicsubstances with water. The sulfonlc acids are then extracted with analcohol such as isoprcpanol to yield an oil substantially free ofsulionic acids and an alcoholic mixture of potroleum sulfcnic acidscontaining only a minor proportion of oil. The alcoholic solution isneu-.- tralized with aqueous guanidine carbonate and the aqueous phaseis separated. The sulfonates are then separated into oil-soluble andsubstantially oil-insoluble guanidine sulfur-rates as previouslydescribed.

While guanidine itself has been the base used to illustrate the varioustypes of sulfonates of our invention. other derivatives of suanidinesuch as alkyl or aryl guanidins, halogen substituted guanidine orcondensed derivatives of guanidine may be used. With variations in thebase it is. necessary to use selected fractions of sulionic acids inorder to secure the desired solub lit characteristics of the product.Examples o the above types of bases are methyl s lani ine..monophenylaucnidine, diphcnyl sua idme, Waxsubstituted suanidines, chloroguanioinrhenrl biguanide. ammelide, diorthotolylsuanidme, amyl guanidine. andthe like. Thus when employing the term a guanidine salt herein it ismeant to include not only suanidine elf but als substituted guanidinesas described above.

The advantages oi this invention are il us trated in the followingexamples. The reactants and their proportions and th ir sp cific ingre-'1 l dients are presented as being typical and should not be construedto limit the invention unduly.

EXAMPLE I Topped Mid-Continent crude was distilled to produce twoseparate distillates corresponding to SAE and raw base stocks. The finaldistillation kettle product or vacuum reduced crude was then subjectedto a two step solvent extraction employing liquid propane as theselective solvent. The propane extract of the first step contained oilof an average viscosity of about 100 SUS 210 F. (SAE base stock) and thepropane extract of the second step contained oil of an average viscosityof about 220 SUS 210 F. (SAE 250 base stock).

The raw SAE 250 base stock was recovered from the total extract of thesecond extraction step and then subjected to solvent extractionemploying phenol as the selective solvent and to propane solventdewaxing to produce a highly paraflinic raflinate comprising alubricating oil stock having the following properties:

A solution of 1000 grams of the lubricating oil stock described abovedissolved in liquid ethylene chloride was slowly mixed with a solutionof 176 grams of sulfur trioxide also dissolved in liquid ethylenechloride at a temperature maintained within the limits of 75 to 115 F.at atmospheric pressure, under which conditions reaction of sulfurtrioxide with the lubricating oil began almost immediately to producepetroleum sulfonic acid. Reaction was completed shortly after admixingof the reactants was terminated.

To the resulting reaction mixture (including ethylene chloride) wasadded 103 grams of guanidine carbonate. The mixture was stirredvigorously at a temperature within the limits of '10 to 110 F., wherebythe guanidine carbonate remixture of guanidine petroleum sulionates,guanidine sulfate, guanidine sulfite and traces of guanidinecarboxylates. Ethylene chloride was then removed from the reactionmixture by vaporization.

The total reaction product, free of ethylene chloride, comprisedguanidine petroleum sulfonates in oil solution and was admixed with anequal volume of anhydrous isopropyl alcohol with vigorous stirring, at atemperature near the boiling point of the alcohol at atmosphericpressure. Under these conditions the guanidine petroleum sulfonatereaction product and oil were dissolved in the alcohol. The alcoholmixture contained some suspended solids and was filtered at its existingtemperature. The filtrate was permitted to cool to room temperature, anda large portion of the solute then separated therefrom, as a gummyviscous liquid. The cooled alcohol solution, i. e., at about 70 F.,containing guanidine petroleum sulfonates not readily dispersible in oilwas decanted from the separated viscous liquid, the latter comprising anoil solution or dispersion of oil-soluble guanidine petroleumsulfonates. The oil solution was then washed with alcohol at roomtemperature and the washings were added to the previously decantedliquid. The remaining alcohol was stripped from the gummy viscousliquid, and the i2 liquid was purified, i. e., freed of occluded salts,by dissolving it in benzene, washing the benzene solution with water,and then stripping until the product was benzene-free. The purifiedproduct consisted of 600 grams of a dark brown, viscous oil solution ofguanidine petroleum sulfonate, and is referred to hereinafter in thisexample as the alcohol-insoluble product, i. e., insoluble at roomtemperature. Several properties of the alcohol-insoluble product arelisted as follows: Specific gravity, 60/60 F. 0.8887 Gravity, API 60 F27.7 Per cent nitrogen 1.08

Alcohol was stripped from the decanted alcohol solution described above.The remaining alcohol-free liquid was purified by dissolving it intoluene, water washing, and then stripping until free of toluene.Toluene was used in the purification of this liquid instead of benzene,in view of its higher boiling point, thus permitting a higher solutionpurification temperature for the guanidine petroleum sulfonates. Theresulting purified guanidine petroleum sulfonates, soluble in isopropylalcohol at 70 F., as compared with the alcohol-insoluble liquiddescribed above, are referred to hereafter in this example as"alcoholsoluble guanidine petroleum sulfonate.

The alcohol-soluble and alcohol-insoluble guanidine petroleum sulfonateswere each incorporated with separate portions of a lube oil base, andeach resulting blend was tested in accordance with the NBS stabilitytest (McKee and Fritz, Analytical Chemistry 21, 568, 1949). In carryingout this test, thermal stability of an oil, in this case a lubricatingoil containing a guani dine petroleum sulfonate as an additive, isdetermined by passing it as a thin film over a steel strip undercontrolled temperature conditions, over a specified period, and theamount of any resulting deposition of degradation product on the stripis measured. Flat steel strips are employed. The tests conducted weremodified in two paracted t acidic t t t to produce a" ticulflrs: theSteel strips Were curved upward at the edges to prevent the test oilfrom running off the sides, and (2) a single 12 hour period was usedinstead or the two 6 hour periods. Each product, i. e., thealcohol-soluble and the alcohol-insoluble guanidine petroleum sulfonate,was added to the base oil in a concentration which yielded anoil-additive solution containing the same number of milliequivalents ofadditive as does a 2 per cent solution of a commercially availabledetergent sold under the trade name of Paranox 64 and comprising analkaline earth metal salt of an alkylphenol sulfide. A blend of the samebase oil with 4 volume per cent of Paranox 64 was tested in the samemanner for comparison. The results of these thermal sta- {oility testsare summarized in the following tabu- 1 A solvent refined SAE 30lubricating oil containii r 0 1 percent of a commereiall availabl xii Y0uni-1e acgeiliterqenes. y L o l .ition iIlLlnllOl, Pass-lt- .e acohol-soluble guanidine etroleum u i solve completely in the base oil. ps l (mate did not dis The alcohol-insoluble guanidh-le petroleumsulfonate was evaluated as a, lubricating oil additive by dissolving itin the base oil already described and then testing the resulting blendin a mounted single cylinder H2 Lauson test engine operated underconditions simulating the CRC test conditions. The test performedconsists f placing 900' grams of the lubricating oil in the crankcase ofthe single cylinder engine and; operating the engine under a 1.2 H. P.load at 1600: R. P. M., while maintaining a cooling Jacket temperatureof 210. E, and oil temperature of 310 E, and an air to Iuel ratio-oi13.51.. At the endoi hours operation under these condithe engine. isstopped, disassembled. and the piston. crankcase. and bearings areexamined. The piston varnishcrankcase. base sludge, overall varnish andcarbon, and overall sludge are rated on an arbitrary scale of l to 10:,the value wrepresenting-as nearly perfect as ascertainab-le, number 1being very poor" and numbers 2 to 9 each representingintermediateratings. As a. standard for further evaluation of the. blendof lubricating; oil and alcohol-insoluble guanidine petroleum sulionate;the same base oil, but without added. guanidine petroleum sulfonate; wastested: in exactly the same manner. The base oil blend. tested containedthe same per cent by weight or the aicnhol -msoluble guanidinepetroiemn.sultonate as used in the strip test described in the foregoingparagraph. For a further comparison, ablend of the same base oil with4.4 volume per cent of a commercially available all detergent sold asLubrizol 67 and comprising a I barium petroleum sulfonate was tested inthe Lauson engine, in the same manner. This latter blend of base oilwith Lubrizol' 6'7 contained the same number of equivalents of sulfonategroups as the tested blend containing guanidine petroleum sulfonate. Thefollowing is a tabulaticn of the results or the Lauson type engine testdescribed:

Solvem refined SAT? 30 luhrlcoiine oil, containing 0.7.) volume percentof a commercially uvailah]. oxidation inhibitor comprising Pia-reactedterpcms.

I This blond contains an amount of Lnhrizol 67 in a concentrationequivalent to the number of active deterrent groups in an oil contaming2 volume percor t Paran ox.

flfis blend-contains an am mm:- of alcohol-insoluble gnanldlnepetroleum. sulsonate'in a cocoon tratioo eenivalent to the number ofactiigi detergent groups in an oil con raining 4 volume percent ParanomThis bleed contains an amozmt o! alcohol-insoluble gumii iire petroleumsnl'onate in a concentration equivalent to We num oer of activedetergent groups in an oil con tain mg 2 volumepm-omt Faranox 64.

The data listed in the preceding tabulationclearly illustrate that theash-free guanidine petroleum sulfonates of our invention are comparablein effectiveness with well established commercial metal-contaimngdetergents.

EXAll/E'LE II A: water solution containing guanidinecarbonate in slightexcess of that required to react with sodium petroleum sulfcnate wasadded with agitation to an aqueous dispersion of a commerciallyavailable sodium petroleum sulionate maintained at 70 F. Under theseconditions the sodium petroleum sulfonate reacted with the guanidinecarbonate to form a firm plastic mass which separated from the resultingreaction mixture, and which upon cooling formed a gel that whilesuitable as a grease was not suitable for use as an oiI detergent. Thisreaction demonstrates that a guanidine petroleum sulfonate detergentmaterial of our invention cannot be prepared merely by reacting acommercially available petroleum sulfonic acid or a salt thereof, with aguanidine salt such as guanidine carbonate. Further, it demonstrates thecommerically available sodium petroleum sulfonate to be sufiicientlywater-soluble to be reactive in aqueous medium with guanidine carbonate.

EXAMPLE III Example I. The petroleum sulfonic acid product was thenconverted to a sodium salt by neutralization with sodiiun hydroxide, andthe total resulting neutralization product was subjected to solventextraction with isopropyl alcohol at room temperature. A portion of aresulting 9; cohol-insoluble sodium salt thus formed; was treated withaqueous guanidine carbonate in ac cordance with the procedure of ExampleII. no reaction appeared to take place and the sodium sulfonate layerwas separated from the aqueous guanidine carbonate layer and thencontacted with a fresh aqueous guanidine carbonate solution. Thesulfonate layer was again separated and water washing was attempted butresulted in formation of a stable emulsion. A sample of the sulfonatelayer upon analysis for nitrogen was found to contain 0.55 per centnitrogen. The sulfated ash content of the sulfonate product wasdetermined and was found to be 4.68 per cent. indicating a high sodiumcontent. These two analytical results indicate that the sodium petroleumsulfonate of this example was substantially unreacted with the guanidinecarbonate. In this regard the sodium petroleum sulfonata prepared from.the SAE 250 Oil, as already described in this example, differs markedlyfrom. the commercially available petroleum sodium sulfonate of ExampleII, inasmuch as in the present example the sodium petroleum sultonate istoo insoluble in water to be reacted with the aqueous guanidinecarbonate. Whereas the commercially available sodium petroleum sulfonatewas sufliciently soluble in water so as to be re acted withguanidinecarbonate.

EXAMPLE IV An additional portion of the isopropyl alcoholinsolublesodium petroleum sulfonate prepared as described in Example III wastreated in the same manner as in Example III except that bark umchloride was substituted for guanidine carbonate. The resulting reactionproduct was an alyzed for sulfated ash. The sulfated ash formed wasleached with water to remove water-soluble ash. The total sulfated ashcontent was 1&2 per cent and the water-insoluble sulfated ash contentwas only 1.6, thus indicating that the alcohol-insoluble sodiumpetroleum sulfonate was substantially unreactiveto form the barium saltiThesedata further distinguish the commercially available sodiumpetroleum sulfonates from the sodium petroleum sulfonates of Example IIIinasmuch as that material can be converted to the barium salt by themethod of this example.

EXAMPLE V Listed as oil compositions I-V in the following tabulation areseveral lube oil blends and also a base oil free of any additivematerial, each of which was evaluated in a series of Lauson engine testsof the type described in Example I. These evaluation tests aresummarized as follows:

(omposltloo I II III IV V cerit. 0.0 0.75 0.5 075 1.00 (lunniriiueocladecvltolwlw sulfo oflnwilgl tr .L 0.0 0.0 0.5 0.0 0.0 U. B. Braydrtergcul. wright pen cent 0.0 0.0 0.0 4.5 4.0

(ommercially available {P195- acted II PGIIPQOIl'lZlt lOII l' liibltor.

The oil employed as the base oil in these compositions was asolvent-refined Mid-Continent oil of lubricating grade having thefollowing characteristics:

The data of Example V illustrate the base oil alone to exhibit desirablepiston varnish ratings and crankcase and base sludge ratings. Howeveruse of the base oil alone results in high bearing weight loss.Accordingly an oxidation inhibitor is employed as illustrated in columnII for the purpose of reducing bearing weight loss. The use of such aninhibitor effectively reduces piston varnish rating, and crankcase andbase sludge rating. Guanidine octadecyltoluene sulfonate, although itcontains only 26 carbon atoms in the molecule and is for that reasonless desirable than are other oil detergents having a larger number ofcarbon atoms in the molecule, provides an improvement in the bearingweight loss and in the varnish rating of the base oil tested.

EXALEPLEVI A guanidine petroleum sulionate detergent was preparedsubstantially in accordance with the procedure outlined hereinbefore.The petroleum sulfonation stock was the same as described in Example I.Batch sulfonation was carried out in a stainless steel vessel by slowlyadding with agitation 450 grams of S03, stabilized againstpolymerization, and dissolved in 2000 grams of ethylene chloride, to4000 grams of oil dissolved in 3000 grams of ethylene chloride. Thesulfonation temperature was maintained at 70 F. throughout the reaction.The reaction mixture was immediately neutralized by stirring in 700 full(ill

grams of commercial guanidine carbonate in the form of an aqueousslurry. The neutralized reaction mixture was washed four times withwater using one volume of wash water per volume of total reactionmixture per wash. The ethylene chloride solvent was evaporated from thewaterwashed product and separation of undesirable guanidine sulfonateswas effected by multiple batch extraction with isopropyl alcohol. Fourbatch extractions were carried out using 2 volumes of the alcohol pervolume of hydrocarbon phase in the first extraction and A; volume ofalcohol in the subsequent extractions. After evaporation of isopropylalcohol from the final extraction residue the yield of guanidinepetroleum sulfonates plus unreacted oil amounted to 2500 grams. Thetotal nitrogen content of this concentrate was 0.96 per cent by weightwhich indicates a guanidine petroleum sulfonate content of about 20 percent by weight.

For purposes of engine evaluation 21.4 weight per cent of the aboveconcentrate was added to a base oil, the same as that of Example I,which contains the oxidation inhibitor primarily to provide bearingprotection for the test engine. Expressed as the number of ionic weightequivalents the preceding blend provides a concentration of guanidineand sulfonate groups exactly equal to that of the barium and phenategroups contained in a 4 volume per cent concentration of the commercialdetergent Paranox 64" in the same base oil, also containing 0.75 volumeper cent of the oxidation inhibitor. The two test oils, therefore, wereexactly equivalent insofar as concentration of surface active groups areconcerned; i. e., two sulfonate molecules per one "Paranox 64 moleculesince the latter contains 2 active phenolic groups per molecule.

Parallel engine tests were completed on both of the above oils using amodified HZ-Lauson engine operating under severe conditions simulatingthe CRC L-l diesel engine test for lube oil detergents. The essentialtest difference between these tests and those of Example I are: oiltemperature 225 F. and jacket temperature, 300 F.

On completion of the tests, the engines were rated as described inExample I to give the following results:

1 T e same us ("ilflfl'jtl in Example 1.

The above results are especially significant inasmuch as Paranox 64 is aqualified diesel oil detergent capable of passing the stringent L-itest. The only unfavorable comparison between the two additives is thatof ring sticking where the actual difference was not as pronounced asthe rating would indicate.

EXAMPLE VII Table 1 gives the physical properties of the white mineraloil used in the preparation and attempted preparation of greases asshown in Table 2.

Table 2 shows clearly how the alkyl aryl sulfonates oi the metalsordinarily used in grease making did not form the proper gels undersimilar conditions as did the corresponding sulfonates of guanidine.Listed across thetop of the table are the various aromatics and theolefins with which they were alkylated. After alkylation. each alkylaromatic was sulfonated and then neutralized to form the salt oftheclement or compound in the left-hand vertical column. In each columnbeneath the particular alkyl aromatic indicated are the results ofattempting to form a grease with the mineral oil described in Table 1.

Table 3 indicates the micropenetration of two of the better greases,those formed with guanidine dodecyltoluene-sulfonate and guanid'iniehexadecyltoluene' sulfona'te; shown in Tame-2, per indicated strokes ofa: grease: worker. The test method used for determining the micropenetration of the greaseis that of the American Society for Testing Materialsand is designatedas ASTM, D217-47T, as modified according to "Industrialand Engineering Chemistry? analytical edition vol. 11, pp. 108-110(1939). The micropenetration is the distance, measured in tenths of amillimeter, which the cone penetrates the grease in seconds. Accordingto this method", an ASTM penetrometer'is usedwith a modified coneweighing 20 grams. Thagrease'of which the penetration' is to be measuredis put in the grease container holding about 3 to s grams and the topsurface leveled off; The container is then placed on the penetrometerbase and tested. The grease worker referred to above is also describedin the indicated ASTM' test method. It briefly comprises a cup with atop for closing through which extends a plunger. Attached to the plungeris a perforated platewhich, when-the grease worker is in operation,passes. back amlforth forcing the grease in the cup to pass through theperforations.

Table 4 showsthe decrease imthe' micropenetration for the gnanidinedodeeyltoliiene sulfonatexgrease, for which the micmpenetrations pcrindicated strokes in the grease 'worker are shown in Table 3; aftersitting undisturbed for the times indicated TABLE. 1

Characteristics of white minem l owused Viscosity at 100? F;sUsamflhamsmuascw M322 Reoersiono; guanidz'na dodecyltolue'ne sulfonateworkedlflOflOO times Total timenisittin'g undisturbr" at'roomtemperature Micropeneinhours tratlcn U: 147 ro. ii 3.5.. 6.0. 40 20.0 4348.0. 40

This example siiowsl another great advantage of ourinventlon. that ofutilizing a mixtureoi oleiiim for alliyl'atlng' the aromatic. In this instance; a fraction of cracliednaphtha boiling in therahg'e" of 24616260Ci ahd containing only 40 per centole'finswasiisedto alliylat'e toluene.This product was stilfon'ated and then neutmnzeeiwitireuanmmmamnatameans. some of whiom were branched, had the double bond in: varicusipetitione izraddition to the 1-position; 'Dhliifiit issh'own thatch!lhVGn-THOTI may bepractioecl i successful!" using easily obitaaine'dwrefinery cuts: mthout extensive piliiffca The grease was l'IIEidB 'bYdispersing 20 parts by weight of the guanicline sulfonate'in parts by.weightof the mineral oil by heating to a temperature ofi between 200 and240 C. and then coolings Tho resulting gel was then milled to asmoothgrea'se.

Table 1 gives thephysicalproperties or the mineral oil used to form thegrease withthe guanidine'aikyiaryi sulfonate.

In Table fithemicropenetration of the grease Viscosity at 2101 t 44.95Prepared as described above is compared with Viscosity index... .l= 9050that of three commercial all-purpose grease Refractive index,.N l l..a.. a.-. 191948: purchased on the open market. Grease" A was p fi y.013690 I a bariumbase grease ma frgm1ub um which Specific dispersion1112 h gelation agent was derived fr m" fatt acid-a Them 2" Radical withmi which'soite e V I a a a v filmed Mothylbuteno-i-benuone camera-mimeDeoonbd-Hohlohe Dodceiie-l-l-lfiuefie" ahauecenar b hiusottlplasticmmsll'ght sombia moiiim gele-.. Soluble moilinozgcihel g3 w1 lab! in 11 Si ht e1 sol b] m u; %iim 6 o m s ollfi lir in oflt wwrswam "iiiamgel. iihfnffisombhmomm SO Calcium smummomnoger -doBolnbiehgoikm s i Ve y taki l Weakgel Weakf'gg1 fi g Guanzid m Insolubleimoflk riog Fairgomui J-.. Good grease:

Great B was a lithium base grease having the TABLE 7 gelation agent madeby treating fatty acids. Commercial grease C is a sodium base grease ofRadicalwm, sane which the gelation agent was made by saponifytrgtgg Reslts ing nonedible tallow with sodium hydroxide. S As may be observed,our grease is equal to or Sodlum..... 17.5 Soluble,no gel. better thanthe comparauve greases Note that Barium... 21.0 Gel after cooling,liquefies after several commercial grease B exceeded a penetration ofGuamdme 5 0 igy s 420, which is about the maximum measuring po l 321Hard, brittle t ay cake, mills to still limit of the penetrometer, afteronly 10,000 greasestrokes in the grease worker.

TABLE 5 Work stability Micropenetration at indicated working strokesChange in micro- Percent change in enertation micropenetraetween 1,000and tion between 1,000 1 00 1,000 5,000 10,000 50,000 100,000 100,000strokes and 100,000 strokes Guanidine alkyl aryl sulfonate 27 52 79 9394 122 140 07 85.

389. cgg mercial greaseA 125 124 145 75 192 244 269 124 80. Commercialgrease B- 158 193 275 380 0 Above 145 at 10,000.. Above 52 at 10,000.Commercial greaseC 53 73 107 137 151 109 237 127 119.

EXAMPLE 1X EXAMPLE XII A soft grease was made by using the guanidinesalt of an alkyl aryl sulfonic acid in which the olefins used inproducing the alkyl aromatic boiled in the range of 190 to 200 0., andthe aromatic was toluene. Only a small portion of the thus formed soapor gelation agent dispersed in the mineral oil used; however, theportion which did, produced a satisfactory soft grease.

EXAMPLE X This example compares in Table 6 the characteristics of ourgrease with a commercial soda base grease of similar character as testedby the conventional grease testing method CRC designation 14-24-745 in awheel bearing tester, built by Precision Scientific Company and asdescribed in the above reference.

TABLE 6 ggfi g Commercial grease worked d 100 000 strokes grease 1 to100,000 strokes testing prior to testing Flow of ease from:

a) gob Very slight- None. Eb) Spindle None--.- Do. Leakage:

(a) Wt.lu grams 3.0.... 0.9. (b) Grease or oil Grease only. Grease andoil. Condition of grease:

(0) Structure change None Slightly more fibrous. (b) Micropenetrationchange. 146 to 54-.. 309 to 61. Condition oi hearing:

(0) Deposits Nona... None. (0) Film of lubricant or dry..." Lubricated"Lubricated.

EXAMPLE XI In this example a white mineral oil, very similar inproperties to that used in the previous two examples, was used. This oilwas admixed with the sodium, barium, and guanidine salts oftrihexyltoluene sulfonic acid under conditions described in thisspecification hereinabove. It is clearly shown by the data in Table '7below that the guanidine salt was the only one which made a satisfactorygrease. It is also shown that a satisfactory grease may be made by usingbetween 5 and 32 weight per cent of the guanidine salt. The sodium andbarium salts used in amounts in about the middle of this range wereunsatisfactory. Although a gel was formed in the case of barium, onsitting for several days, it becomes a liquid again.

Salt Solubility in oil Guanidine laurate. Insoluble, stratified oncooling. Guanidine stenrste Hard waxy cake, worked to poor grease.Pitlililylhigllmii ie cero- Poor grease.

In reiteration, advantages of our invention are the manufacture of agood lubricating grease from products of petroleum, thus eliminating thenecessity of using animal and vegetable fatty acids; the production of asubstantially ashless grease; the utilization of compounds notordinarily satisfactory for grease making; and utilization of particularrefinery cuts without extensive purification.

As will be evident to those skilled in the art, various modificationscan be made or followed, in the light of the foregoing disclosure anddiscussion, without departing from the spirit or scope of the disclosureor from the scope of the claims.

We claim:

1. A method for the manufacture of an oil detergent, comprisingsulfonating a deasphalted and solvent-refined petroleum bright stockcontaining at least 40 carbon atoms in the molecule, neutralizing aresulting sulfonic acid with a guanidine compound selected from thegroup consisting of guanidine and a basic guanidine salt, resultingneutralization product containing oilsoluble and oil-insoluble guanidinepetroleum sulfonates, separating oil-soluble guanidine petroleumsulfonates from oil-insoluble guanidine petroleum sulfonates is saidneutralization product, and recovering said oil-soluble guanidinesulfonate as a detergent product of the process.

2. A method for the manufacture of an oil detergent. comprisingsubjecting a deasphalted and solvent-refined petroleum bright stockhaving at least 40 carbon atoms in the molecule to sulfonation employingsulfur trioxide as a sul- 23 alkyl aryl sulfonic acid containing from 24to 70 carbon atoms in the molecule.

23. The composition of claim 21 wherein said oil-soluble salt is aguanidine salt of a petroleum sulfonic acid containing from 40 to 70carbon atoms in the molecule.

24. In the oil lubrication of engine parts during operation of anengine, wherein oil deteriorative reactions take place to form oilsludge, and wherein said oil sludge deposits and accumulates on theengine parts to cause general malfunction, the improvement of preventingsaid deposition and accumulation of sludge, comprising lubricating saidengine parts with a lubricating oil containing from 0.1 to 25 weight percent of an oil-soluble guanidine salt of an organic sulfonic acidselected from the group consisting of a synthetic alkyl aryl sulionicacid and a petroleum sulfonic acid.

25. The improvement of claim 24 wherein said guanidine petroleumsulfonic acid contains from 40 to 70 carbon atoms in the molecule.

26. The improvement of claim 24 wherein said alkyl aryl sulfonic acidcontains from 24 to 70 carbon atoms in the molecule.

27. As a new class of compositions, guanidine petroleum sulfonatescontaining more than 20 carbon atoms in the molecule.

23. A mineral oil-soluble guanidine petroleum sulfonate derived from apropane fractionated solvent refined petroleum bright stock having aviscosity within the limits of 80 and 700 SUS at 210 F.

29. A guanidine salt of a petroleum sulfonic acid containing from 40 to70 carbon atoms in stock and then neutralizing the petroleum sulfonicacid thus formed, with guanidine.

32. A diguanidine salt of a petroleum disulionic acid containing from70-80 carbon atoms in the molecule.

33. A lubricant containing at least 0.1 weight per cent of guanidinedodecyltoluene sulfonate.

34. A lubricant containing at least 0.1 weight per cent of guanidinehexadecyltoluene sulfonate.

35. A lubricant containing at least 0.1 weight per cent of guanidinetrihexyltoluene sulionate.

36. A lubricant comprising a sufiicient quantity of a guanidine alkylaryl sulfonate containing at least 10 carbon atoms in the alkyl groupsdispersed in a mineral oil to cause an increase in the viscosity of theoil.

37. A lubricant comprising 5 to 60 weight per cent or a guanidine alkylaryl sulfonate containing to carbon atoms in the alkyl groups in mineraloil.

38. A lubricating grease comprising 15 to weight per cent of a guanidinealkyl aryl sulfonate containing a total or 10 to 20 carbon atoms in thealkyl groups dispersed in mineral oil.

39. A lubricant comprising a sufiioient quantity of a guanidine alkylaryl sulfonate dispersed in a mineral oil having a viscosity index above60 to cause an increase in the viscosity of the oil, wherein the totalnumber of carbon atoms in the alkyl groups of said sulfonate are withinthe range of 10 to 20.

40. A lubricating grease comprising 5 to 60 weight per cent of aguanidine alkyl aryl sulfonate, wherein the total number of carbon atomsin the alkyl groups is at least 10, dispersed in a mineral oil having aviscosity in the range of 50 to 4000 SUS at F., wherein said sulfonateis prepared by alkylating an aromatic hydrocarbon with olefins boilingin the range of 230 to 250 0., sulionating the alkylated aromatichydrocarbon, and forming the guanidine salt of the sulfonate.

4 A lubricating grease comprising 5 to 60 weight per cent of a guanidinealkyl aryl sulfonate dispersed in a mineral oil having a viscosity inthe range of to 500 SUS at 100 F., wherein the alkyl groups of saidsulfonate contain a total of 10 to 20 carbon. atoms per molecule.

42. A lubricating grease comprising 5 to 60 weight per cent of aguanidine alkyl aryl sulfonate.

wherein the total number of carbon atoms in the alkyl groups is at least10, dispersed in a mineral oil having a viscosity in the range of 125 to500 SUS at 100 F., wherein said sulionate is prepared by allgylating anaromatic hydrocarbon with olefins boiling in the range of to 315 C'.,sulfonating the alkylated aromatic hydrocarbon. and forming theguanidine salt thereof.

43. A lubricating grease comprising 15 to 50 weight per cent of aguanidine alkyl aryl sulfonate dispersed in a mineral oil having aviscosity in the range of 50 to 700 SUS at 100 F., wherein the alkylgroups of said sulfonate contain a total 01' 10 to 20 carbon atoms permolecule.

44. A lubricating grease comprising 15 to 50 weight per cent of aguanidine alkyl aryl sulfonate, wherein the total number of carbon atomsin the alkyl groups is at least 10, dispersed in a mineral oil having aviscosity in the range of 50 to 700 SUS at 100 F., wherein saidsulfonate is prepared by alkylating an aromatic hydrocarbon selectedfrom the group consisting of benzene, naphthalene, diphenyl, anthracene,and their lower alkyl homologs with olefins boiling in the range of 190to 315 0., sulfonating the alkylated aromatic, and forming the guanidinesalt thereof.

45. A polyguanidine petroleum polysulfonate containing one sulfonategroup per 20 to 35 carbon atoms.

WILLIAM N. AXE. WILLIAM B. WHITNEY.

References Cited in the file Of this patent UNITED STATES PATENTS NumberName Date 2,052,586 Tucker Sept. 1, 1936 2,055,588 Pospiech Sept. 29,1936 2,076,623 De Groote et a1. Apr. 13, 1937 2,223,935 Daniels et a1.Dec. 3. 1940 2,422,243 Knutson et al. June 17, 1947

11. A LUBRICATING OIL CONTAINING IN SOLUTION FROM 0.1 TO 25 WEIGHT PERCENT OF AN OIL-SOLUBLE GUANIDINE SALT, OF AN ORGANIC SULFONIC ACID,SELECTED FROM THE GROUP CONSISTING OF A SYNTHETIC ALKYL ARYL SULFONICACID AND A PETROLEUM SULFONIC ACID.
 27. AS A NEW CLASS OF COMPOSITIONS,GUANIDINE PETROLEUM SULFONATES CONTAINING MORE THAN 20 CARBON ATOMS INTHE MOLECULE.